<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Title</title>
</head>
<body>

<div id="app">
  <cpn><span slot="center">替换了中间</span></cpn>
  <button slot="left">返回</button>
</div>

<template id="cpn">
  <div>
    <slot name="left"><span>左边</span></slot>
    <slot name="center"><span>中间</span></slot>
    <slot name="right"><span>右边</span></slot>
  </div>
</template>

<script src="../js/vue.js"></script>
<script>
    const app = new Vue({
        el:'#app',
        data:{
            message:'你好呀'
        },
        components:{
            cpn:{
                template:'#cpn',
            },
        },
        methods:{

        }
    })
</script>
</body>
</html>